Rescue Elizabeth using only tanks
Beat the first arena
Help your allied army win their battle
Access the water area in the first level
Beat all 4 final arenas
Beat the survival mode in 45 seconds or less
Found all 14 upgrade gears
Beat the final boss
Kill 50 vehicles using Mech's sword
Kill 50 vehicles using the flamethrower
Kill 50 vehicles using Gatling's hammer
Kill 50 vehicles using the ramming plough
Kill 50 vehicles using drivers